1. Field of the Invention
The invention relates to air conditioning condensing fans and, more particularly, to a fan and housing which temporarily replace an existing condensing fan in an air conditioning unit.
2. History of the Prior Art
Air conditioning units operate on the principle known as the refrigeration cycle. In a closed-loop air conditioning system, a coolant is circulated through a series of pipes and heat exchangers, from which no coolant escapes, and eventually returns to its starting point. The coolant starts the cycle in a liquid state and travels to a heat exchanger where heat energy from the space to be cooled is absorbed by the coolant. The added heat vaporizes the coolant which then enters a condenser in the air conditioning unit.
Air conditioning units rely on condensers to condense coolant in the air conditioning system from a gaseous state to a liquid state, after the coolant has absorbed heat energy from the volume being cooled. In order to achieve this condensation, condensers utilize condensing fans to draw or blow cooling air over a set of condensing coils which contain the coolant. As the coolant travels through the coils, its heat is conducted through the coils where it is carried away by the flow of air created by the condensing fan.
The condenser and condensing fan are generally located outdoors where the heat can be dissipated into the surrounding atmosphere. In the summertime, air conditioners are operated for many hours per day, and condensing fans must operate in very high ambient temperatures. This environment is very strenuous on electric motors, and the failure of condensing fans is a common source of air conditioning outages in both residential and commercial air conditioning units.
The only economically viable solution for a failed condenser fan is to replace the fan. Air conditioning service technicians must obtain a new fan, either from stock or from a supplier, transport it to the air conditioner site, and remove and replace the failed fan.
There are many different types, sizes, and brands of condensing fan motors, and the technician must replace the failed fan with a condensing fan which is compatible with the customer's particular air conditioning unit and mounting frames. However, due to the size of a typical condensing fan, a technician cannot stock many fans on his service truck. It is very difficult for a service technician to carry even the most commonly used condensing fans, and he almost never carries the rarer types. Therefore, when a rare type of condensing fan fails, it is highly likely that the service technician will not have a replacement fan on his truck. As a consequence, the air conditioning unit is without cooling air, and out of service until a replacement fan can be obtained.
In larger cities, where air conditioning supplies are plentiful, the technician may be able to obtain a replacement fan within a few hours. In smaller towns and in rural areas, where supplies are not as plentiful, the problem is much worse; it may take several days to obtain the proper fan, and the customer is without air conditioning for that entire period. Additionally, it may take days to obtain rarer types of condensing fans no matter where the unit is located.
In order to reduce this delay, many air conditioning technicians maintain a large inventory of condensing fans in their shops. This adds to their cost of doing business since some fans may sit on the shelf for years before they are needed.
Additional cost and delay is experienced in checking out the air conditioning system when the service technician finally replaces the condensing fan after a lengthy outage. Long delays in resuming air conditioning allow the temperature in the air-conditioned space to rise significantly. When the temperature in the space to be cooled is hot, the coolant absorbs a greater amount of heat energy, vaporizes more completely, and rises to a higher temperature and pressure. As a consequence, the temperature and pressure inside the condenser run higher than normal. The technician must wait for the condenser pressure to return to the normal range to complete the check-out of the system. The pressure in the condenser does not return to normal until the temperature in the space to be cooled returns to its normal range. This causes additional delay to the technician and expense to the customer.
It would be a distinct advantage for air conditioning service technicians to have a temporary condensing fan which can be used to temporarily provide a cooling of air to an air conditioning condenser when its existing fan fails. Moreover, it would be advantageous to have this portable condensing fan mounted in a housing which may be compatibly mounted on any brand of air conditioner unit. It would also be advantageous to have the fan easily and quickly mounted and wired into the air conditioner system, and to have an adjustable air flow in order to adjust the condenser's head pressure so that the refrigeration cycle could work as efficiently as possible.
The portable condensing fan of the present invention offers such a fan. The portable condensing fan of the present invention temporarily supplies cooling air, and enables the customer to remain in air conditioned comfort, until a permanent replacement fan is obtained and installed. The air temperature, therefore, remains cool in the air conditioned space, thereby maintaining the condenser pressure in its normal range, and greatly reducing the time for system check-out, following final replacement of the condensing fan.
Additionally, the portable condensing fan of the present invention lowers the cost of air conditioning services by allowing technicians, to reduce their inventory. By carrying one portable condensing fan, a service technician significantly lowers his required inventory of condensing fans, while providing better service to his customers.